Preheat the oven to 170°C/340°F. Line a 16 cm round cake tin with baking paper.

Beat the eggs with the sugar and vanilla until pale and fluffy.

Add the yogurt and whisk until smooth.

Separately sift the flour and whisk it with the cinnamon and baking powder.

Combine the wet and dry ingredients until a smooth batter forms.

Peel and core an apple, cut it into cubes, and fold it into the batter.

Pour the batter into the prepared tin and spread it evenly.

Arrange another apple, cored and thinly sliced, on top.

Drizzle with melted butter and bake for 1 hour 30 minutes.